1. Technical Field
This disclosure relates to electronic circuits, and more particularly, to circuits arranged to prevent damage resulting from electro-static discharge.
2. Description of the Related Art
Electro-static discharge (ESD) is a sudden electrical current flow between two charged surfaces. Often times, a significant difference in voltage potential may exist between the two charged surfaces. When the surfaces are electrically shorted together, come into contact, or dielectric breakdown occurs therebetween, the surfaces may discharge until the difference in voltage is effectively zero. Since the voltage difference prior to discharge may be large, the corresponding currents during discharge may also be large.
Semiconductor devices (e.g., integrated circuits, or ICs) may be particularly vulnerable to the adverse effects of ESD. The large currents that can be produced by ESD can damage or destroy circuitry. Accordingly, during manufacturing and installation of electronic systems utilizing ICs, special handling procedures may be followed to prevent ESD damage from occurring. Furthermore, many ICs may have ESD protection circuitry built in. Such circuitry may include a sensor and a clamp circuit. The sensor may sense the occurrence of an ESD event. Responsive to sensing the ESD event, the sensor may cause activation of the clamp circuit to provide an electrical path through which the current may be safely discharged.